Development of groundwater resources for Indian tribes in the west revolves around Winters Doctrine rights and the McCarran Amendment, which established Practical Irrigable Acreage (PIA) as the yardstick to quantify water rights. PIA claims are a complex interrelationship among economic, hydrogeologic, market, agricultural, and soil scientists to jointly develop appropriately scaled and economically viable irrication projects.Hydro Geo Chem, Inc.has extensive experiece in providing expert services to resolve water rights disputes.